The invention relates to a substrate holder having a base plate. The invention also relates to a plasma reactor for depositing diamond, comprising such a substrate holder, and to a method for depositing diamond from the gas phase.
Such a method is known from WO 2003/040440 A2. In this known method, a monocrystalline diamond is arranged as a substrate on the base plate of a substrate holder and heated to a temperature of above 900° C. by means of an assigned heating device. Plasma containing hydrogen, nitrogen and methane is ignited above the surface of the substrate. A diamond layer is subsequently deposited on the substrate at a growth rate of 1 to 3 μm/h. The diamond layer deposited from the gas phase grows with the crystal direction predetermined by the substrate, and therefore it is also possible to deposit a monocrystalline diamond layer in the case of a substrate from monocrystalline diamond.
However, this known method has the drawback that individual substrates from monocrystalline diamond only have a small size. In order to efficiently carry out the method, the base plate of the substrate holder can be equipped with a plurality of substrates which can be coated at the same time. However, the drawback is that these individual substrates are then interconnected by a polycrystalline diamond layer deposited from the gas phase. Thereafter, the individual substrates must be separated upon conclusion of the growth process, e.g. by being removed using the laser cutting method. This damages the substrate holder, and therefore a new substrate holder always has to be provided for the repeated conduction of the method.